1. Field of the Invention
The invention relates to a driving support system and a driving support apparatus which provide a driver driving a vehicle with information on another vehicle whose estimated path will intersect with an estimated path of the vehicle through vehicle-to-vehicle communication. More particularly, the invention relates to a driving support system, a driving support apparatus and a driving support method which make it possible to accurately determine whether there is a possibility that an estimated path of a vehicle driven by a driver will intersect with an estimated path of another vehicle, even in the vehicle without a map database.
2. Description of the Related Art
As disclosed in Japanese Patent Laid-Open Publication No. 4-290200, a system or an apparatus has been developed which enables an exchange of running data such as present position information, running speed information and running direction information between vehicles through vehicle-to-vehicle communication, and which gives a warning to a driver driving a vehicle when detecting that there is another vehicle that is approaching an intersection ahead of the vehicle.
However, the technology disclosed in the above-mentioned publication can be realized only when the vehicle which employs the system or the apparatus is provided with a map database. Namely, it is determined whether there is a possibility that an estimated path of the other vehicle will intersect with an estimated path of the vehicle by checking the received position of the other vehicle against the map database.
Varieties of performance, specifications and equipment of vehicles running on ordinary roads are broad, and not all the vehicles are provided with a map database (and a navigation system or the like for using the map database) that is relatively expensive. In a vehicle without a map database, when a running vector of another vehicle is compared with a running vector of the vehicle, a road state is not taken into consideration. Accordingly, even when there is the other vehicle running on a road that does not intersect with a road on which the vehicle is running, it may be determined that an estimated path of the other vehicle will intersect with an estimated path of the vehicle. Meanwhile, even when there is the other vehicle running on a road that intersects with the road on which the vehicle is running, it may be determined that the estimated path of the other vehicle will not intersect with the estimated path of the vehicle.